Trembler switch



Dec. 10, 1968 H R, KOLLMEYER 3,415,960

TREMBLER SWITCH Filed July 50. 1957 Hmmm n. KUL/.MEYER BY n. MMI fj, Wj i @Wawy-9M United States Patent O 3,415,960 TREMBLER SWITCH Herman R. Kollmeyer, Washington, D.C., assignor to the United States of America as represented by the Secretary of the Army Filed July 30, 1957, Ser. No. 675,233 2 Claims. (Cl. Z110-61.49)

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to trembler switches, and more particularly to trembler switches providing relatively long durations of closed contact.

In the past and at present, trembler switches have found wide applications in various ordnance missiles. Upon a predetermined acceleration of a missile mounting such a switch, the switch usually closes an electric circuit l to facilitate accomplishment of some desirable result on `or by the missile, for example, arming a fuze during launching or ydetonating a pyrotechnic material at impact with a target. However, known trembler switches are not capable of providing suiciently long contact closure times for many applications. Where it is essential that a power supply feed current for a relatively long period of time to an electronic component when a predetermined short acceleration is attained, a relatively long switch closure time is necessary. To sufficiently heat some detonator bridges and filaments with relatively low voltage power supplies, such as miniature single-cell batteries, obvious-ly will require suitable continuance of current. These and many other specific applications have been hindered by the absence of a trembler switch conducive to prolonged current feeding.

Accordingly, it is a principal object of this invention to provide a `trembler switch capable of presenting relatively lasting contact closures at predetermined missile accelerations.

Another object is to provide a tremb-ler switch adapted to remain open during missile launching and free flight and adapted to remain closed at missile impact long enough to achieve intended results.

Still another object is to provide a trembler switch that will close substantially instantaneously at predetermined missile accelerations.

A further object is to provide a trembler switch that is relatively small in volume and inexpensive to manufacture.

In general, the present invention contemplates a flexible displacement conductive member spaced from a relatively fixed conductor. A weight is mounted on and displaceable with the flexible member. When the flexible member, and consequently the weight, is subject to a predetermined acceleration, the member will contact the fixed conductor,

thus closing an electrical circuit. The flexible member will then flex on the fixed conductor and with the aid of the weight will deflect until a restraining means contacts the weight. Upon a decrease of the acceleration, the inertial forces acting on the flexible member and Weight will subside. Subsequently, the flexible member will assume its original configuration, thus breaking contact with the fixed conductors. Therefore, the electronic circuit will be closed throughout the period that the flexible member is in a substantially deflected condition and not merely when the weight is in contact with its restraining means.

The specific nature of the invention as well as other objects, uses and advantages thereof will clearly appear from the following description and from the accompanying ldrawing, in which:

FIGURE l is a longitudinal section of a trembler switch according to the present invention.

3,415,960 Patented Dec. 10, 1968 FIGURE 2 is a cross-section taken substantially along the line 2-2.

FIGURE 3 is similar to FIGURE l and illustrating another embodiment of the invention.

FIGURE 4 is similar to FIGURE l and illustrating still another embodiment of the invention.

Referring to FIGURE l, the trembler switch of the present invention comprises a hollow cylinder 10 having a bore 12 extending longitudinally throughout its length. Cylinder 10 is formed from an insulating material, such as a well-known resin. For reasons that will become apparent shortly, cylinder 10 is provided with a reduced boss section 14. As is more clearly illustrated in FIGURE 2, bore section 14 is circular in cross-section and has its axis offset from the longitudinal axis of thecylinlder 10.

An electrically conductive plug 16 having a bored recess 18 is located at one end of cylinder 10. Distal board recess 18 and suitably mounted on plug 16, as by solder 20, provides a conductive terminal 22. Terminal 22 normally facilitates securement of the trembler switch to electronic components and circuitry.

At the other end of cylinder 10 is an insulating plug 24. As shown, plug 24 is formed with bore 26 terminating in a tapered bore 28 which in turn communicate with a reduced bore 30. Plug 24 is also provided with an annular flange 32 for abutment with the corresponding end of cylinder 10.

It will be observed that reduced bore section 14 forms annular shoulders 34 and 36 with main bore 12. These shoulders, 34 and 36, may advantageously serve as a stop means for controlling Athe insertion of plugs 24 and 16 into bore 12 as illustrated.

Extending through bores 26, 28, and 30 and into bore 12 is a wire or filament 38, preferably resilient, is provided, with suitable insulation 40. A hollow rivet or eyelet 42 is inserted in bore 30 to secure filament 38 to plug 24, either mechanically or with the aid of adhesive or solder. The free end 44 of filament 38 is conveniently disposed in bore 18 of plug 16 and is spaced from the walls thereof. It is preferable that filament 38 possess some degree of flexibility and elasticity.

A weight 46 of suitable configuration is secured to filament 38 in any convenient manner to be displaced therewith. Weight 46 is provided with a coaxial bore 48 to permit the necessary ilexure or bending `of filament 38v as will become evident shortly. Allixed in the Asp'ace provided between rivet 42 and plug 24 and extending to and suitably aflixed to Weight 46 is spring 50. As illustrated, spring 50 is helical in form and conforms externally to the contour presented by bores 26, v2.8 and 30. Spring 50 functions to impart the necessary flexibility and elasticity to filament 38 for some specific applications. Obviously spring 50 furnishes added restoring forces that will act on weight 46 in the event that weight 46 is displaced from its normal position. In the embodiment of FIGURES 1 and 2 it is immaterial whether or not weight 46 and spring 50 be conductive or not.

The embodiment of FIGURE 1-2 may be termed a unidirectional trembler switch, since proper switch closure is possible only when filament 38 is displaced in substantially one direction. This is due to weight 46 abutting the side walls of reduced bore section 14, thus preventing end 44 of filament 38 from contacting the side walls of bore 18 of conductive plug 16. However, it will be observed that when filament 38 is displaced in the direction of arrow 52 (FIGURES 1-2), and within limits in directions that approach that indicated by arrow 52, end 44 will be permitted to contact the side walls of conductive plug 16. When sufficient inertial forces are present weight 46 will cause the filament 38 to displace quickly to contact plug 16 and to deflect or bend. The maximum displacement of weight 46, and consequently the maximum deflection and displacement of filament 38, is governed by the minimum space between the weight 46 and cylinder 10 in the direction of displacement. When the inertial forces subside the deflection will tend to decrease. End 44 of filament 38 will remain in Contact with the side walls defining bore 18 until the deflection of the filament betwen plugs 24 and 16 is nil. The end 44 of filament 38 will disengage plug 16 and return to its normal position. Thus it will be observed that end 44 of filament 38 will be in contact With plug 16 substantially longer than weight 46 will be in contact with cylinder 10. The various critical conditions of defiection of filament 38 may be represented by the dash and dot-dash lines illustrated in FIGURE 3.

The unidirectional deflection feature of the embodiment of FIGURES 1-2 is extremely desirable, but it should be apparent that a multideiiection fabrication can be employed or reduced bore section 14 be dispensed with entirely.

Referring now to FIGURE 3, another embodiment of the invention is disclosed which does away with the unidirectional feature and spring 50. The remaining parts are fabricated substantially the same as those of the embodiment of FIGURES 1-2. The omission of spring 50 provides for a trembler switch with decreased restoring means to act on Weight 46. Consequently, the switch closure or contact time, that is, the time end 44 contacts plug 16 upon deiiection of filament 38, will be increased. Some degree of stiffness is lost by the omission of spring 50, thus rendering the switch more sensitive to lower inertial forces due to accelerations. The functioning of the trembler switch of FIGURE 3 in all other respects is substantially similar to that of the embodiment of FIGURES 1-2.

Referring now to FIGURE 4, a further embodiment of the invention is presented. The essential parts 'of this embodiment are substantially the same as those of FIGURES 1-2. However the embodiment of FIGURE 4 dispenses with the unidirectional deflection feature and a portion of filament 38 betwen rivet 42 and weight 46. The functioning of this embodiment is substantially the same as that of FIGURES 1-2 with the exception that a switch is provided that is more sensitive to lower g inertial forces. Addition ally, relatively longer switch contact times are experienced.

It will be apparent that the parameters of the individual elements of the several embodiments of the present invention may be varied to arrive at different sensitivities, switch closure durations and proper functioning at predetermined accelerations.

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as defined in the appended claims.

I claim as my invention:

1. A trembler switch which closes for a sustained period of time in response to forces which act on said switch only for a short period of time, said switch comprising: an insulative cylinder having first and second open ends; an insulative plug disposed in the first end; a conductive plug disposed in t-he second end, said conductive pl-ug having a cylindrical bore therein; a round resilient filament in said cylinder, one end of said filament fixed in said insulative plug, the other end of said filament being free, said filament being capable of bending in all directions, the longitudinal axes of said filament, cylinder and cylindrical bore being substantially coaxial, the extremity of the free end of said filament extending into said cylindrical bore, said extremity being spaced from the walls of said bore when said longitudinal axis of said filament is substantially coaxial with the longitudinal axes of said cylinder; a weight positioned within, and spaced from the inner walls of said cylinder; said weight positioned intermediate the fixed and free ends of said filament; a coaxial bore through the longitudinal axis of said weight, said bore also being coaxial to said longitudinal axis of said filament and serving to fix said weight to said filament intermediate said fixed and free .ends thereof, said weight pressing said extremity of said filament into contact with said bore when said weight is forced towards and against said inner walls of said cylinder in response to forces acting in any direction on said switch, said weight thereupon bending said filament substantially intermediate said fixed and free ends, causing said extremity to remain in contact with said bore for a period of time before and after said weight element contacts said inner walls of said cylinder.

2. The trembler switch as defined in claim 1, in which a helical spring is positioned within said cylinder and surrounds that lportion of said filament betwen said fixed end and said weight, the longitudinal axis of said spring being substantially coaxial to said longitudinal axis of said filament, said spring having one end fixed in said insulative plug and the other end fixed to said weight.

References Cited UNITED STATES PATENTS 700,585 5/1902 Vial ZOO-61.51 1,846,966 2/ 1932 Hausse 20D-61.49 2,344,854 -3/ 1944 Dempsey 20G-61.49 2,634,407 4/ 1953 Johnson 20G-61.49

RODNEY D. BENNETT, Primary Examiner.

C. E. WANDS, Assistant Examiner. 

1. A TREMBLER SWITCH WHICH CLOSES FOR A SUSTAINED PERIOD OF TIME IN RESPONSE TO FORCES WHICH ACT ON SAID SWITCH ONLY FOR A SHORT PERIOD OF TIME, SAID SWITCH COMPRISING: AN INSULATIVE CYLINDER HAVING FIRST AND SECOND OPEN ENDS; AND INSULATIVE PLUG DISPOSED IN THE FIRST END; A CONDUCTIVE PLUG DISPOSED IN THE SECOND END, SAID CONDUCTIVE PLUG HAVING A CYLINDRICAL BORE THEREIN; A ROUND RESILIENT FILAMENT IN SAID CYLINDER, ONE END OF SAID FILAMENT FIXED IN SAID INSULATIVE PLUG, THE OTHER END OF SAID FILAMENT BEING FREE, SAID FILAMENT BEING CAPABLE OF BENDING IN ALL DIRECTIONS, THE LONGITUDINAL AXES OF SAID FILAMENT, CYLINDER AND CYLINDRICAL BORE BEING SUBSTANTIALLY COAXIAL, THE EXTREMITY OF THE FREE END OF SAID FILAMENT EXTENDIKNG INTO SAID CYLINDRICAL BORE, SAID EXTREMITY BEING SPACED FROM THE WALLS OF SAID BORE WHEN SAID LONGITUDINAL AXIS OF SAID FILAMENT IS SUBSTANTIALLY COAXIAL WITH THE LONGITUDINAL AXES OF SAID CYLINDER; A WEIGHT POSITIONED WITH, AND SPACED FROM THE INNER WALLS OF SAID CYLINDER SAID WEIGHT POSITIONED INTERMEDIATE THE FIXED AND FREE ENDS OF SAID FILAMENTS; A COAXIAL BORE THROUGH THE LONGITUDINAL AXIS OF SAID WEIGHT, SAID BORE ALSO BEING COAXIAL TO SAID LONGITUDINAL AXIS OF SAID FILAMENT AND SERVING TO FIX SAID WEIGHT TO SAID FILAMENT AND SERVING TO FIX SAID ENDS THEREOF, SAID WEIGHT PRESSING SAID EXTREMITY OF SAID FILAMENT INTO CONTACT WITH SAID BORE WHEN SAID WEIGHT IS FORCED TOWARD AND AGAINST SAID INNER WALLS OR SAID CYLINDER IN RESPONSE TO FORCES ACTIDNG IN ANY DIRECTION ON SAID SWITCH, SAID WEIGHT THEREUPON BENDING SAID FILAMENT SUBSTANTIALLY INTERMEDIATE SAID FIXED AND FREE ENDS, CAUSING SAID EXTREMITY TO REMAIN IN CONTACT WITH SAOID BORE FOR A PERIOD OF TIME BEFORE AND AFTER SAID WEIGHT ELEMENT CONTACTS SAID INNER WALLS OF SAID CYLINDER 